• 제어로봇시스템학회논문지
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• 제14권3호
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• pp.295-300
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• 2008

In this paper, a new looper controller is proposed to minimize the tension variation of a strip in the hot strip finishing mill. The proposed control technology is based on a receding horizon control (RHC) to satisfy the constraints on the control input/state variables. The finite terminal weighting matrix is used instead of the terminal equality constraint. The closed loop stability of the RHC for the looper system is analyzed to guarantee the monotonicity of the optimal cost. Furthermore, the RHC is combined with a 4SID(Subspace-based State Space System Identification) model identifier to improve the robustness for the parameter variation and the disturbance of an actuator. As a result, it is shown through a computer simulation that the proposed control scheme satisfies the given constraints on the control inputs and states: roll speed, looper current, unit tension, and looper angle. The control scheme also diminishes the tension variation for the parameter variation and the disturbance as well.

• 제어로봇시스템학회논문지
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• 제11권9호
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• pp.755-760
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• 2005

This paper proposes an improved implementation algorithm for the continuous-time receding horizon control (RHC). The proposed algorithm has a feature that it has better control performance than the existing algorithm. Main idea of the proposed algorithm is that we can approximate the original RHC problem better by assuming the predicted input trajectory on the prediction horizon has a continuous form, which is constructed from linear interpolation of finite number of vectors. This, in turn, leads to improved control performance. We derive a predictor such that it takes linear interpolation into account and proposes the method by which we can express the cost exactly. Through simulation study fur an inverted pendulum, we illustrate that the proposed algorithm has the better control performance than the existing one.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2471-2473
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• 2005

We present a receding horizon control [RHC] algorithm for compensation of backlash at the input of a stable linear system under control rate constraints. The problem is posed as a receding horizon optimal control [RHOptC] problem for a piecewise affine [PWA] system by modelling the backlash nonlinearity as a PWA system with a state space partition consisting of three regions. The RHC problem involves solving, at each step, $3^N$ quadratic programmes[QP], where N is the optimization horizon. This strategy leads, at the cost of some performance degradation, to much smaller computational load since a feasible rather than optimal solution has to be obtained at each step.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.659-664
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• 2000

Fuel-consumption and catalyst-out emissions of a parallel hybrid electric vehicle are affected by operating region of an engine. In many researches, It is generally known that it is profitable in fuel- consumption to operate engine in OOL(Optimal Operating Line). We established the mathematical model of a parallel hybrid electric vehicle, which is linear time-invariant. To operate an engine in OOL, we applied RHC(Receding Horizon Control) to the driving control of a parallel hybrid electric vehicle. And it is known that the RHC has advantages such as good tracking performance under state and control constraints. This RHC is obtained by using linear matrix inequality (LMI) optimization. In this paper, there are three main topics. First, without state and control constraints, the optimal tracking of OOL was simulated. Second, with state and control constraints by engine and motor performances, the optimal tracking of OOL was simulated. In the last, we studied on the optimal gear ratio. That is to say, we combined the RHC and the iterative simulation to extract the optimal gear ratio. In this simulation, the vehicle is commanded to track the reference vehicle trajectory and the engine is operated in the optimal operating region which is made by the state constraints.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2441-2446
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• 2009

무선 센서 네트워크는 특정지역에서 데이터를 수집하여 처리는 작은 센서 노드들로 구성된다. 이러한 센서들은 최초로 설치된 이후에는 배터리로 동작되며, 동작기간이 수개월에서 수년까지 지속되어야 함으로 제한된 자원을 효율적으로 활용할 수 있어야 한다. 본 논문에서는 데이터 중심개념을 적용한 Directed Diffusion의 기본동작구조에 RHC(rounting history cache)를 적용하여, 데이터 전송경로 설정에 신뢰성과 효율성을 높인다. 제안하는 RHC 알고리즘은 각 센서 노드가 자신의 RHC를 주기적으로 업데이트 하여 최적화경로를 저장하고 있기 때문에, 이벤트 발생시마다 경로를 재설정하여 에너지가 낭비되는 것을 최소화하였고, 중복메시지의 최소화로 신뢰성을 향상시켰다.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.140-144
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• 2010

In the case of a linear time-varying system, it is difficult to apply the conventional stability conditions of RHC (Receding Horizon Control) to real physical systems because of computational complexity comes from time-varying system and backward Riccati equation. Therefore, in this study, a frozen time RHC for a linear discrete time-varying system is proposed. Since the proposed control law is obtained by time-invariant Riccati equation solved by forward iterations at each control time, its stability can be ensured by matrix inequality condition and the stability condition based on horizon for a time-invariant system, and they can be applied to real physical systems effectively in comparison with the conventional RHC.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.1018-1021
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• 2009

무선 센서 네트워크는 특정지역에서 데이터를 수집하여 처리는 작은 센서 노드들로 구성된다. 이러한 센서들은 최초로 설치된 이후에는 배터리로 동작되며, 동작기간이 수개월에서 수년까지 지속되어야 함으로 제한된 자원을 효율적으로 활용할 수 있어야 한다. 본 논문에서는 데이터 중심개념을 적용한 Directed Diffusion의 기본동작구조에 RHC(rounting history cache)를 적용하여, 데이터 전송경로 설정에 신뢰성과 효율성을 높인다. 제안하는 RHC 알고리즘은 각 센서노드가 자신의 RHC를 주기적으로 업데이트하여 최적화경로를 저장하고 있기 때문에, 이벤트 발생시마다 경로를 재설정하여 에너지가 낭비되는 것을 최소화 하였고, 중복메시지의 최소화로 신뢰성을 향상시켰다.

• Advances in robotics research
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• 제2권2호
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• pp.161-182
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• 2018

This paper proposes a novel receding horizon control (RHC) algorithm for formation control of a swarm of unmanned surface vehicles (USVs) using particle swarm optimization (PSO). The proposed control algorithm provides the coordinated path tracking of multi-agent USVs while preventing collisions and considering external disturbances such as ocean currents. A three degrees-of-freedom kinematic model of the USV is used for the RHC with guaranteed stability and convergence by incorporating a sequential Monte Carlo (SMC)-based particle initialization. An ocean current model-based estimator is designed to compensate for the effect of ocean currents on the USVs. This method is compared with the PSO-based RHC algorithms to demonstrate the performance of the formation control and the collision avoidance in the presence of ocean currents through numerical simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.633-635
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• 1999

We design to the temperature control system based on Receding horizon control(RHC) with a terminal output weighting for stochastic state model. This system has a large time delay, a nonlinear temperature characteristics, a perturbation, a disturbance, etc. In this paper, we show that RHC can easily be applied to the system to track the desired temperature, since it takes the receding horizon strategy for both controller and filter.

• Advances in robotics research
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• 제1권1호
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• pp.41-59
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• 2014

This paper deals with the problem of steering a group of mobile robots along a reference path while maintaining a desired geometric formation. To solve this problem, the overall formation is decomposed into numerous geometric patterns composed of pairs of robots, and the state of the geometric patterns is defined. A control algorithm for the problem is proposed based on the Nash equilibrium strategies incorporating receding horizon control (RHC), also known as model predictive control (MPC). Each robot calculates a control input over a finite prediction horizon and transmits this control input to its neighbor. Considering the motion of the other robots in the prediction horizon, each robot calculates the optimal control strategy to achieve its goals: tracking a reference path and maintaining a desired formation. The performance of the proposed algorithm is validated using numerical simulations.